1. Field of the Invention
The disclosed embodiments of the invention relate to electromagnetic radiation suppression methods, and more particularly, to LC tank electromagnetic radiation suppression methods and associated apparatuses.
2. Description of the Prior Art
Electronic products emit electromagnetic radiation when powered on and operating. This electromagnetic radiation may interfere with the normal operation of neighboring electronic products and may also affect public health. As a result, most countries have set Electromagnetic Interference (EMI) regulations on electronic products.
The integrated circuit (IC) is a major electromagnetic radiation source, especially the inductor inside an IC. The electromagnetic radiation emitted by the inductor not only interferes with external electronic devices, but also with internal components' operation. When a differential mode LC tank has mismatched equivalent inductance between the positive and negative terminals, a common mode signal emerges from the junction of the positive and negative terminals. The common mode signal then wanders on metal lines electrically connected to the junction and induces electromagnetic radiation.
As a result, how to reduce the differential and common mode electromagnetic radiation of the LC tank without affecting performance and reduce the mismatch between the positive and negative terminals of the differential mode LC tank has become an issue in the field.